I have a few ponderings on the mechanics of the Floo Networks. Can you be transported to any fireplace through the network, or does some kind of spell need to be cast in order to make it a 'Floo Stop'?
And if no spellis really need, what are the requirment for someone being able to transport by Floo? Does it need to be a fireplace? What if there isn't one anywhere close? Can a bon fire be used, a burning trash can, an oven?
I'm still wondering. What do all of you think?
"Floo" makes me think it has to be fireplaces, not any convenient fire, and "network" implies an infrastructure, which means you have to build it. So I don't think wizards can just go from any fireplace in the world to any other fireplace. I think they need to specifically add a fireplace to the network. (Obviously they did this to the Dursleys' fireplace, while Harry was living there.)
We know you have to toss Floo Powder into the flames and say where you want to go. So there is a spell involved. And Harry wound up in Knockturn Alley when he mispronounced his destination, so the "routing" mechanism is capable of misunderstanding and making errors.